Search results

Search Forums New Posts
  1. N

    Can Batteries Exhibit Resonance at Particular Frequencies?

    So you are asking about benefits of pulsed DC charging? Is this related to a resonance in the battery? Sorry, can't really see where the resonance comes in. At what sort of Q-factor do we consider it a resonance worth thinking about?
  2. N

    Which type of sensor works for pigeons within 20 feet without tripping when a skytrain drives by

    If you use FMCW then I guess there is pulse compression to a narow pulse (time-width about one over the bandwidth) or multiplication with the local reference to get a frequency that depends on range (assuming low Doppler). The Acconeer radar I pointed you to, is interfaced as a digital device...
  3. N

    Please confirm this capacitor value....

    0.0047uF = 4.7nF = (47 x 100)pF = 47x10^2pF ==> "472"
  4. N

    JAKES LADDER

    Maybe an easier test is to hold it horizontally, or slightly upside down?
  5. N

    JAKES LADDER

    Hot air?
  6. N

    PLA imlementation

    Do they give different answers? truth tables? Perhaps one simply has redundant connections. Maybe you need a minimal one in some form, or perhaps it does not matter. . If for example, using normal logic rules, you could show that your upper table were able to be logically reduced to the Karnaugh...
  7. N

    Soliciting advice: Starting an online embedded systems career

    Sorry, can't help with the questions, but one comment, If arduino is really just a selection of boards with a common interface, you might want to also list as having some experience with the processor range that powers arduino boards, including arduino, as some users may be looking for the...
  8. N

    PLA imlementation

    What makes you think that one is wrong?
  9. N

    Need Help with simple 9V circuit design.

    The LP2950 is a regulator bringing the 9v down to 5 volts for the touch switch. According to https://theorycircuit.com/lp2950-adjustable-micropower-voltage-regulator-circuit/ pin 3 should go to the 9v, pin 2 to gnd and the output is pin 1. . The Fet provides that extra current capability that I...
  10. N

    Need Help with simple 9V circuit design.

    grr. can't cut and paste the link form the image. http://www.icstation.com/10pcs-ttp223-capacitive-touch-switch-touching-button-switch-module-self-lockingno-locking-module-arduino-p-12675.html No. Proably not as you have drawn it. This switch needs power to it always, so not used in series as...
  11. N

    Which type of sensor works for pigeons within 20 feet without tripping when a skytrain drives by

    There is an absorption line in air at 60.5GHz. The attenuation increases dramatically about this frequency. . You message is a good one: You can't get over the large distance object versus the near smaller object, but the move of some things to 60GHz to contain the field of effect is also real...
  12. N

    tens of years battery life ?

    Not something that I do every day, but, ... (2.2Ah * 2) capacity of two batteries (Room temperature) (0.01*0.01*3) drain per hour (2.2 * 2)/(0.01*0.01*3) = hours of life = 14,667 hours 14,667/(24*365) = 1.67 years . Did I go wrong?
  13. N

    Which type of sensor works for pigeons within 20 feet without tripping when a skytrain drives by

    The Acconeer radar unit is at 60GHz. It will only propagate so far in air. This somewhat aleviates the distant elephant issue. Doppler radar may be possible if the train you mention has a different heading to the pigeons and you can get the unit in line with the direction of travel. Again, the...
  14. N

    Which type of sensor works for pigeons within 20 feet without tripping when a skytrain drives by

    PIR? A111 Acconeer radar? . Mount it on the ceiling, pointing down at the floor?
  15. N

    boolean Algebra

    Sorry, which line can't you get to? is it from = (K+LM)(N+LQ)(P+MQ) to = (KN+KLQ+LMN+LMQ)(P+MQ) . Or was it getting to = (K+LM)(N+LQ)(P+MQ)? . Do not follow your " given the formulas in the text". Do you think of (K+LM)(N+LQ) in terms of algebra or as [K or (L and M)] and [N or (L and Q)]? ...
  16. N

    Problem understanding an answer given to a question in 'Complete Electronics Self-Teaching Guide'.

    Here's the original which asks about the same at 1Amp and answers about 1 amp https://www.oreilly.com/library/view/complete-electronics-self-teaching/9781118282328/c02_level1_2.xhtml Same figure number. Seems to support the theory of a change in the question, but not in the answer text.
  17. N

    Far-field antenna polarization...

    Weak from no LOS and abundant scattering or weak from just being a low-level signal, eg range for power and sensitivity. . Even if there is line of sight and the range, powers and sensitvity is such that the signal is small, all the normal polarisation rules hold, including that you can...
  18. N

    Power line adapters

    Your configuration is not entirely obvious to me, but I guess if A-B is givng you 350MBytes per second, or was it bits? and A-C was giving you 150 of the same, then B-C, if such routing is seimilar would give you no more than 150MBytes per second, if it must go B-A-C. Does it go B-A-C? What rate...
  19. N

    Far-field antenna polarization...

    Polarisation depends on the transmitter. Look up for what's used where you are. Yes, horizontal is common. . Scattering. When the horizontally-polarised waves hit that randomly angled roofing iron, or buildings, or hills they scatter at rather unpredictable angles and polarisations. So, in a...
  20. N

    True flash ADC

    Even cascading LM3914s the resolution is limited. I suspect that there are cheap, computer-based scopes available. Perhaps a USB one might do?
Top